Cooling system



Feb. 11, 1941. D. PICA COOLING SYSTEM Filed July 9, 195a Patented Feb. 11, 1941 UNITED STATES PAT ENT OFFICE COOLING SYSTEM Daniel Pica, Chicago,

Ill., assignor to Frank 5 Claims.

This invention has to do with an air cooling system for cylinders. It is particularly adapted to internal combustion motors using reciprocatory and rotatory pistons, an example of which is disclosed in my co-pending application, Serial No. 81,091 filed May 21, 1936. It may equally well be used, however, with any internal combustion engine having the conventional reciprocatory pistons, with air compressors, or wherever cooling becomes a consideration.

As is well known, air cooling systems have lon been in use for internal combustion engines, although for the most part, in theautomobile field, they have been superseded by circulatory liquid systems. As the size and the horsepower of an engine is increased, a point is reached in the conventional air cooling system, even when used in airplanes, where it is impossible adequately to cool the engine. Under such circumstances it becomes necessary to use a circulatory liquidsystern. which carries with it disadvantages in cost, added weight per horsepower of from 20 to 45 per cent, and added bulk.

My invention makes it possible to air cool an internal combustion engine of any size irrespective of the weight or horsepower involved, and in any type of engine, whether the cylinders be disposed radially, are opposed, or are in the conventional series V type, or otherwise, of the automobile engine. The same is equally true of any type of compressor.

In the accompanying drawing,'Fig. 1 is a plan view of the cylinder head of my engine.v Fig. 2

is a view along the line 2-2 of Fig. 1, partly in section and partly in side elevation. Fig. 3 is a view along the line 2-2 of Fig. 1, partly in section and partly in side elevation, the cylinder however, containing a piston of the conventional reciprocatory type.

Rotatory engines In the preferred application oi my invention to an engine having a reciprocatory and rotatory piston, Fig. 2 shows a cylinder I having a cylinder head I I. Within the cylinder is a piston I2 having a skirt I3 adapted to engage closely a slot or chamber I4 between the well of the cylinder head II and the cylinder wall I0. In Fig. 2 the piston I2 is shown at the bottom. point of its stroke on an explosion. In the side of the cylinder wall I0 is a cam track I5 following the path of a sine curve, being semi-circular in cross section. The curve of the cam track is shown by the dotted lines on Fig. 2. On opposite sides of the piston I2 are a pair of semi-spherical depressions I6, I6

having a radius similar to the maximum radius of the cam. track I5. Between the cam. track I5 and the semi-spherical depressions I8, It in the piston is a pair of cam followers l1, l1 sized to fit closely in the depressions I6, I6 and the cam track I5. In the base of the piston I2 are a pair of cylindrical wells I8, I8 which are snugly engagedby a pair of cylindrical rods I9, I9 fixed to a ily wheel 20. The piston I2 is free to move upward and downward upon the rods I9, I9 thus translating a rotatory and reciprocatory motion of the fly wheel and the drive shaft 2|.

Means for admitting fuel and emitting exhaust are found in the orifice 22 in the piston skirt I3 and are more particularly explained in my copending application Serial No. 81,091. It will be understood that the orifice 22 is traveling the path of a sine curve during a cycle of the engine. At suitable points along the path of this curve, the orifice 22 engages slots 23, 23 shown in the dotted lines on Fig. 2, in the cylinder wall I0, through which fuel is admitted or the exhaust drawn off.

It will further be understood that the necessity for cooling an engine arises from the intense; heat created by the explosion of the fuel at the top of the stroke. At this position on my engine, the bottom of the piston well is in juxtaposition to the gap on the spark plug 25 and the skirt of the piston completely fills the annular slot I4. When the explosion occurs the piston is given a downward impulse and the skirt I 3 begins to recede in the slot or chamber I4. As the slot or chamber I4 is connected with the ambient atmosphere throughorifices 24 in'the cylinder head I I, air is sucked'into the slot with the result that a I cooling medium having normal atmospheric temperature is'introduced into very close proximity with the seat of the greatest amount of heat. On its up stroke, the skirt I3 rises to fill the annular slot or chamber I4 expelling the heated .air through the orifices 24 and drawing in on the suction stroke, a new supply of air having an atmospheric temperature. Thus it will be seen that in a four-cycle engine, air having an atmospheric temperature is twice circulated in close proximity to the point of explosion at the top of the cylinder, which has the effect oi completely cooling the engine to the same or a greater degree than the circulation of water in the cylinder jacket. In a two-cycle or intermittent type of engine, air is drawn into the chamber I4 on every reciprocation of the piston I2. It will further be seen that whereas the water in a circulatory system quickly reaches a temperature in close proximity to the boiling point, which is maintained throughout the operation of the engine, the air which is used to cool my cylinder is at an atmospheric temperature.

Reciprocatory engines The application of my invention to a conventional engine is shown in Fig. 3, the piston [2 being provided with a skirt I3 adapted to engage an annular slot or chamber 14 in the top of the cylinder head. Said engine also comprises a wrist pin 26, a connecting rod 21, a crank shaft 28 and a crank case 29. Fuel is admitted through the registration of orifices 3U, 30 with slots 3|, 3|, shown in dotted lines in the cylinder Wall, said slots being connected by passageways with conventional poppet valves, not shown, The only difference in operation between the engines shown in Figs. 2 and 3 arises from the fact that in the conventional engine shown in Fig, 3, the piston l2 does not rotate. The oscillation of the skirt I3 in the slot or chamber nevertheless produces the result of pumping in a supply of air having atmospheric temperature on each down stroke and expelling it on each up stroke to keep the engine in such a condition that it will operate without any other cooling system.

In both Figs. 2 and 3 I have shown fins 32 on the outside wall of the cylinder Hl. These form no part of my invention, and it is to be understood that my cooling system will cool an engine for an indefinite period without assistance of fins on the outer wall of the cylinder, or the circulation of ambient atmosphere therethrough.

Compressors It is to be understood of course that the application of cooling problems is not confined to in- .ternal combustion engines where heat is created as the result of an explosion, but may also arise in compressors where heat is created as a result of the compression of gases. While I have not shown the application of my invention to a compressor in the drawing, any one skilled in the art will readily perceive how a compressor can be designed with a sleeved piston, the sleeve moving backward and forward in an annular slot or chamber which is connected by orifices or passageways with the ambient atmosphere. function of the sleeve and the slot or chamber is The the same whether it be associated with an engine or with a compressor.

Independently actuated air pumps It is further to be understood that the annexed drawing is simply illustrative of my cooling system. While the devices disclosed in Figs, 2 and 3 tion of air, and the circulation of air need not necessarily be confined to the region of the annular slot or chamber I4 shown in Figs. 2 and 3, but air may further be circulated through passageways in the cylinder jacket H], or around the valves if that be desired.

Having fully described my invention, I claim:

1. In a cooling system, the combination of a cylinder having an annular chamber between the cylinder head and the cylinder-wall, apiston having a skirt adapted to reciprocate in said annular chamber, and a continuous connection between said annular chamber and the ambient atmosphere, the location of said chamber and connection being such with reference to said cylinder head and wall that upon the retrogression of said piston from the top of its stroke there is approximately immediate contact of the ambient atmos phere with the surface of both said cylinder head and wall within said chamber, said surface of contact increasing as said piston retrogresses.

2. In a cooling system, the combination of a cylinder having an annular chamber between the cylinder head and the cylinder wall, a piston having a skirt adapted to reciprocate and rotate in said annular chamber, and a continuous connection between said annular chamber and the ambient atmosphere.

3. In a cooling system, the combination of a cylinder having explosion means, an air chamber within said cylinder in close proximity to said explosion means,said air chamber being directly and continuously connected by a passageway with the ambient atmosphere, and reciprocating and rotating means to fill said chamber with air and exhaust the same following an explosion in said cylinder. I

4. In a cooling system, the combination of a cylinder, a piston in said cylinder, a source of heat developed by the movement of said piston in said cylinder, an air chamber within said cylinder continuously and directly connected with the ambient atmosphere in close proximity .to said source of heat, and reciprocating and rotating means connected with said piston, so constructed and arranged that said chamber is filled with turbulent air and exhausted during the movement of said piston in said cylinder.

5. In a cooling system, the combination of a cylinder having an annular chamber between the cylinder head and the cylinder wall, a piston having a skirt adapted to reciprocate and rotate in said annular chamber, and a continuous connectionv between said annular chamber and the ambient atmosphere, the location of said chamber and connection being such with reference to said cylinder head and wall that upon the retrogression of said piston from the top of its stroke there is approximately immediate contact of the ambient atmosphere with the surface of both said cylinder head and wall within said chamber, said surface of contact increasing as said piston retrogresses.

DANIEL PICA. 

